Electric self-winding clock.



E. A. HUMMEL.

ELECTRIC SELF WINDING CLOCK.

APPLICATION FILED APR. 16. 1908.

Patented Feb. 27, 1917.

2 SHEETS-SHEET 1 [WW/M7; EmeJfAHJ/W W UNITED STATES PATENT OFFICE.

ERNEST A. HUMMEL, OF ST. PAUL, MINNESOTA, ASSIGNOR TO ALBERT L. HAMAN, OF

' ST. PAUL, MINNESOTA.

' ELECTRIC SELF-WINDING CLOCK.

I Specification of Letters Patent.

Patented Feb. 27, 1917.

Application filed April 16, 1908. Serial No. 427,361.

To all whom it may concern:

Be it known that I, ERNEST A. HUMMEL, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Electric Self-Winding Clocks,'of which the following is a specication.

My invention relates to improvements in self winding clocks, its object being particularly to provide a construction whereby the clock may be wound to run for longer periods than the ordinary constructions and consists of other features of improvements hereinafter more particularly described and claimed.

In the accompanying drawings forming part of this specification,

Figure 1 is a front elevation of a portion of clock movement embodying my improvements, v

Fig. 2 is a similar View of certain features of my invention partly broken away,

Fig. 3 is a side elevation of a clock embodying my invention,

Fig. 4 is a section on line wm of Fig. 3, and

Fig. 5 is a section on line g 1 of Fig. 1.

Referring to the drawings AA desig- Hate the front and rear plates of a clock movement which plates are connected by suitable rods 2 and provide bearings for the I several parts of the clock mbvement. Between said plates is mounted the minute wheel 3 so secured to a shaft or arbor 4 as to allow of some intermediate play. The shaft is connected in the usual manner to a train of gears controlled by an escapement device Upon the minute hand shaft is rotatably mounted a fly wheel 6 having formed upon its face a hub 7. Arranged within the hub 7 and connecting the same with the sleeve 8, inclosing the arbor and upon which the hub turns, is the main spring 9. In order to turn the minute hand shaft I provide a pawl 10 carried by the fly wheel and engaging with the flanged ratchet wheel 11 mounted upon the shaft 4 at the rear of the minute hand wheel. A safety dog 12 engages with said ratchet wheel as shown in Fig. 1. The shaft 4 is connected with the minute hand wheel by means of a coil spring 13.

Supported upon the inside of the clock are the electromagnets 14 the armature 15 of which has pivotal support 16 upon the frame and has its inner end bent to form a lever arm 17, the arm 17 extending inwardly across the rear face of the fly wheel. Carried by the fly wheel in position to be engaged by the lever arm 17 is a roller 18 whereby when the armature 15 is attracted by themagnet it will, by means of the engagement of the arm 1 with said roller, rotate the fly wheel to wind up the main spring. In order to energize the electromagnets, I provide the knife switch contact 19 supported upon the frame of the clock and electrically connected by means of a wire 20 with the magnet. 'l'laving pivotal support 21 upon the hub 7 is a switch blade 22 normally held in full line position by the spring 23. As the fly wheel turns in the normal movement of the clock the switch blade is brought into contact first with the spring arm 21 secured to the upper side of the contact 19. The continued movement of the fly wheel turns the knife blade upon its pivot against the tension of its spring until it slips by the end of the arm 21 when its spring 23 will carry it with sudden impact into engagement with the contact 19 as shown in Fig. 2. In contacting position the blade abuts against the finger 23 upon the arm 22. The closing of the circuit through the switch energizes the electromagnets and attracts the armature as shown in Fig. 1,

throwing the arm 17 against the roller 18- and turning the flywheel. The stronger the current the more sudden will be the impact of the lever 17 with the roller 18 and the farther the fly wheel will be carried by momentum.

During the period of the fly wheels beingcarried by momentum to wind up the main spring, the clock work will be kept running by means of the pressure of the spring 13. The lever 12 engaging with the ratchet wheel will prevent the return movement of the ratchet wheel, thus holding said wheel immovable upon the shaft 4 and forming a fixed support for the inner end of the spring 13, allowing the spring 13 to exert pressure llt will thus be evident that the stronger the battery and consequently the stronger the attraction of the armature the farther the fly wheel will be turned upon its shaft and the longer the time will be between windings. Consequently the maximum use of the battery is obtained.

1 claim as my invention:

In an electric clock, the combination with a rotary spring winding element, of an electro-magnet, an armature in said magnet, a fixed contact in circuit with said electromagnet, a movable contact also in said circuit with said magnet and pivoted upon said spring winding element, said movable contact being spring pressed into normal position, means for causing sa1d movable contact to snap into engagement with said fixed In testimony whereof ll affix my signature in presence of two wltnesses.

ERNEST A. HUMMEL.

Witnesses H. S. JOHNSON, HATTIE SMITH. 

